Chain saw guard



United States Patent Inventor Maurice M. Cairns Roseburg, Oregon Appl. No. 721,429 Filed April 15, 1968 Patented Sept. 29, 1970 Assignee Sylvanus R. Hunt, doing business as Snively Wedge Co., Roseburg, Oregon a sole proprietorship CHAIN SAW GUARD 2 Claims, 7 Drawing Figs.

U.S. C1 143/321, 143/159 Int. Cl B27b 17/00 Field of Search 143/32,

[56] References Cited UNITED STATES PATENTS 2,826,294 3/1958 Nicodemus 143/32 3,040,790 6/1962 Goodson 143/32-13X 3,292,671 12/1966 Stromberg 143/32 Primary Examiner Donald R Schran Attorney-Buckhorn, Blore, Klarquist and Sparkman ABSTRACT: A chain saw guard in the form of a C-shaped channel member which has converging legs which are spreadable t0 fit onto the saw bar and its chain, wherein each leg has a stop lug to engage behind a raised portion of the chain to releasably retain the member on the chain saw against inadvertent endwise dislodgment.

Patented Sept. 29, 1910 3,530,910

FIG. 7

MAURICE M. CAIRNS INVENTOR BUCKHORN, BLORE, KLARQUIST 8. SPARKMAN ATTORNEYS CHAIN SAW GUARD.

Prior chain saw guards of which I am aware have in general comprised eitherv l) a cloth sock which encloses the saw bar and its chain, but this allows the saw bar chain to sweat and rust, or (2) a perforated plastic cover which is rather expensive. l am also aware of the guardshown in the patent to Tyrrell, No. 3,129,721, wherein the walls of the guardconverge inwardly so that they must be forcibly spread apart to fit over. and snap into engagement with the saw bar.

The chain saw guard of the present invention comprises a guard member, as describedin the abstract (above) whichhas resilient legs which can be spreadapart. to enable, the guard to fit onto the saw bar and. its chain, and has stop lugs to releasably retain the guard member inplace.

FIG. 1 shows in solidlines my guard mounted on a saw bar and its chain, and shows in broken lines the leg portions of the guard in spread condition for application to the saw bar and chain;

FIG. 2 is a view of the saw guard in its relaxed and undistorted condition;

FIG. 3 is a vertical section taken along line 3-3 of FIG. 2;

FIG. 4 is a view of a modified form of guard;

FIG. 5 is a fragmentary side view. of another modified form of guard;

FIG. 6 is a view of the clamping band of FIG. 5; and

FIG. 7 is a fragmentary side view of a guard lilte that in FIGS. 1 and 2 but which is differently constructed at the curved portion of the guard.

Referring to FIGS. 1 and 2, the chain saw guard comprises a molded plastic guard memberll of generally C-shape having elongate legs 13 and 15. The legs converge toward one another in the undistorted, condition of the guard for a purpose to be described.

The guard member comprises an outer wall 17 and inwardly extending parallel side walls 19- and 21 so that the guard member is U-shaped in cross section througho ut. I

At the curved portion 18 of the guard, member, a pair of gusset portions 18a are molded integrally with the side walls 19 and 21. A reinforcing bead 22 is formed onthe inner margin of each wall and extends around the inner margin of the associated gusset.

The spacing betweenthe side walls 19 and 21 ofa leg of the guard member is substantially uniform from the outer wall 17 to the inner free margins 22a of such side walls. This spacing is slightly greater than the thickness of the saw chainv 23. so that the guard will freely fit over the chain without having to spring the side walls apart.

Each of the legs 13 and has a retainer or stop lug 25 formed thereon near the free end thereof. FIG. 3 shows that each lug extends across the Channel provided by the associated leg, and is integrally joined to the side walls and outer wall of its leg. Each lug terminates short of the inner margins 22:; of the side walls of its leg so that it can fit behind a raised portion of the chain 23 and be accommodated within one of the spaces or gaps providedby the teethand linl'gs of the chain. Thus the lugs do not interfere with nor prohibit the chain from being covered by the side walls ,of the legs of the guard member 11.

The legs 13 and 15 are flexible sothat. they can be sprung apart from their FIG. 2 positions to their broken line positions in FIG. I for the purpose of dispgsingthe lugs25 outwardly of the chain to enable the guard member to be moved into enclosing relation with respect to the chain. Thereafter the legs are released to allow them to snapintoplace in clarnping relation against the chain. The. clamping action is achieved because the legs, when in contact with the chain, will be held outwardly of their normal undistorted positions. lnthe event the lugs 25 do not fall into gapsin the chain, the guard member and/or chain may be shifted slightly to effect this result. The lugs can fit in the gaps provided by the chain links 29 or they can fit in the gullets 31 of the teeth 33. The lugs, when in place, prevent endwise dislodgment of the guard member from the saw bar and its chain. Thus, the guard member is releasably retainedinplace on the chain saw until it is removedv by springing the legs 13, and 15 apartand rnoving the guard member to the left, as the parts are shown in FIG. 1. The guard member has a length slightly less than the exposed portions of the bar and chain so that the guard encloses and protectssubstantially the entire exposedchain portions.

FIG. 4 shows a modifiedfqrm of guard wherein each leg has two retaining lugs, the leg 15a shown in FIG. 4 having lugs labeled 25a. v 'i FIGS. 5 and 6 show a modifiedform of guard having legs 13!: and 15b each, having across-sectional shape the; saineas legs 13 andl S. Legs 13) 'andlsb have no retainer lugs 2 5 am insteadeach legv has a pin on the outer wall thereof near the free end of the leg. An ela s tomer retainerband shown in plan in FIG. 6 is formedwith an eye at each entl.

The guard is applied. to a saw bar and. its chain. Then one eye 45 is fitted onto a pin 41. Next, the band is wrapped several times around the guard and saw bar assembly and the other eye fitted onto the other to hold the guard: in clamping relation to the saw bar andichain.

FIG. 7 shows a guardm llber 5l which is formed like the guard member of F IG. 2 except that guard member 51 has no gusset P on 18 d es guardnimbe ,1-v

Having described thev invention inwhat is considered to be the preferred embodiment thereof, it desired that it be understood that the invention, is not to be limited other than by the provisions of the following claims. I V l I claim:

lfA guard for application to a chain saw: i

said guard comprising a generally C-shaped guard member having elongate legs which have predetermined positions relative to one. another in the und' rted of said member, but w i a b m srar l s nets we: a spreading force, and in such spread condition arejurged by the stresses set up in said member to. return to said p ed e ned relat o s Y said guard member being defined by an outer wall and ce r lel generally wa d y xtndi iss lew the edges of said sidewalls being spaced apart a distance greater than the width of the saw chain on a saw so as to readily pass over such chain when the guard member is being ppl t th a said guard member being of a length just short of that of the length of the exposed portion of the saw bar to which it is to be applied; V I I i es nv rs n W d i anot e an a $49. tha the end portions of saidlegs are spaced from one another a distance less than the overall width, of the bar and saw chain to which it is to be applied, so that the legs have to be sprung apart to be applied to the saw bar and saw chain, and when the spreading force is released, said legs in tending to return to said predetermined positions will contact the saw chain whereby to clampingly engage the same, whereby said guard member is retained onthe saw, in a direction widthwise of the saw blade, solely by said clamping action; I

said guard being retained on the, saw in a direction normal to the saw blade by said side flanges whieh act as' retainers;

each leg of saidguard memher having adjacent its free end and interiorly thereof a chain engaging stop. lug to behind a raised portion of chainand retain said guard member on saidsaw in a direction lengthwise of the saw q n said guard member being retained on the. saw blade and chain solely by the combination of the clamping action of said legs, the retaining action of said sidewalls and the stopping action of said lugs. I l I '7 2. A chain saw guard comprising:

a generallyvC-shaped guard member having elongate leg I portions;

said member being defined by an outer wall and spaced, generally parallel inwardly extending sidewalls so that it is U-shaped incross section throughout; i

said member being of a length just short of that of the exeach leg having an outwardly projecting pin thereon, and a posed portion of the saw bar to which it is to be applied; stretchable band having a length at least several times the means to retain the guard member on a saw bar and its distance between the legs and wrappable around the chain against accidental dislodgment; and guard and having eyes to fit on the pin. 

